Battery operated alarms serving to detect a single hazardous condition or disturbance and sound an alarm are known in the art. Although requiring very little power, the prior art devices are also relatively simple and have limited alarm features and effectiveness. U.S. Pat. No. 4,758,824 of Young is typical of such devices. The alarm device can be attached to a venetian blind for sensing motion of the blind. U.S. Pat. No. 4,418,337 of Bader teaches an alarm device which can be attached to a person's clothing for monitoring the person's movement. Although both of the devices may be compact and battery operated, they also are very limited in detection application.
The alarm system of the present invention provides a multipurpose, comprehensive and highly efficient battery powered alarm system in contrast to mono-dynamic, battery operated sensing detection devices of the prior art. The invention affords a battery powered control unit which can have its own intrusion sensor, and can accept inputs/outputs from other sensing devices as well as to activate external alarm and signalling devices.